Hitherto, there have been known lenses having a small diameter of about 0.5 to 3.0 mm, such as a selfoc lens used in a copying machine and an optical fiber for optical comminucation, which have not been called microlens.
A selfoc lens is a hard lens exhibiting no pliability, and an optical fiber is not a plane lens though it has pliability. In the case of forming an image on an image receiving material, therefore, the original is not read as a whole at once but linearly, taking a long time to read the whole image of the original. Further, when an image on a curved surface of the original is formed on a plane surface, a hard lens such as a selfoc lens cannot form the image from all portions of the original. Furthermore, an image formation on a square surface using a tube shaped light source encounters the problem that the image at the periphery of the square surface becomes fuzzy.